Interpretive Summary: Wheat leaf rust, stem rust, stripe rust, and powdery mildew caused by fungal pathogens are destructive diseases of wheat worldwide. The most effective and widely utilized defense against these diseases is the use of host resistance. The importance of wheat production combined with the recent emergence of highly virulent stem rust pathogen races demands new and enhanced sources of resistance. We found a new resistance gene in a wheat mutant that is resistant to these aforementioned wheat diseases. This resistance gene could be used to develop wheat varieties that are Beneficial to growers by reducing losses caused by rusts and mildew in wheat production.

Technical Abstract:
Wheat leaf rust, stem rust, stripe rust, and powdery mildew caused by the fungal pathogens Puccinia triticina, P. graminis f. sp. tritici, P. striiformis f. sp. tritici, and Blumeria graminis f. sp. tritici, respectively, are destructive diseases of wheat worldwide. The most effective and widely utilized defense against these biotrophic pathogens is the use of host resistance. The majority of identified rust and mildew resistance genes are race-specific. The relatively recent evolution and domestication of hexaploid wheat resulted in limited allelic variations among disease resistance genes. The importance of wheat production combined with the recent emergence of highly virulent stem rust pathogen races demands new and enhanced sources of resistance. Here we describe a new race-non-specific resistance gene, obtained by mutagenesis. The mutant, MNs220Alp, enhances resistance to three rusts and powdery mildew. Genetic analysis demonstrated that the resistance in MNs220Alp is conferred by a single dominant gene. Gene expression profiling of several pathogenesis-related genes indicated that MNs220Alp has an elevated and rapid pathogen-induced response. In addition to its potential use in breeding for resistance to multiple diseases, continued analysis of the disease resistance locus in MNs220Alp may lead to a better understanding of the regulation of defense responses in wheat.